and may provide renewed support for politics willing to challenge the powerful nra lobby. newyork senator criticized the nra vice president's argument that any attempt at gun restrictions is bound to fail. >> i think he is so extreme and tone deaf he helps the cause of us passing sensible gun legislation in the congress. >> reporter: a number of democratic congressmen pledged to -- reintroduce bans and certain restrictions on ammunition. many fear those new laws and are are voting with their pocketbook. at a denver gun show this weekend, ammunition for the ar- 15 semiautomatic rifle, the style of weapon used in the newtown attack sold out within an hour. >> we are worried we will not be able to keep our guns for our safety and we are not doing anything wrong. >> reporter: it is not clear yet if the nation's second worst school shooting actually drives washington to change any gun laws. but a review from cbs news indicates schools in at least a dozen states are looking at the nra's call to add armed officers or to allow teachers to carry weapon. >> cbs news, washington. >>>